Jacket for cylindrical article and method and apparatus for forming said jacket

ABSTRACT

A duct of thermal insulation is jacketed with a gas impermeable sheet material with a longitudinal seam formed by turning the mating ends of the sheet material outwardly and thermally fusing those ends into a linear nodular bead. In the case of metal foils of a few thousandths of an inch in thickness the bead is of the order of a thirty-second of an inch and is turned into the foil jacket to present a smooth non-cutting surface. Semi-butt welds of foil are made by clamping the foil in face to face relationship along an essentially line contact and moving an arc welding electrode with associated gas jets for a nonoxidizing gas parallel to and in close spaced relation to the clamp line. Jacketing for preformed ducts of glass or other fiber type insulation is drawn from a supply of sheet stock to form a catenary loop in which a preformed duct is placed. Jaws forming unitary clamps and welding electrodes are closed to close the opposite sides of the loop of foil around the duct and upon each other. The foil is severed closely adjacent the clamps and the electrode with its jets for the gas is moved along the exposed edges of foil adjacent the electrode clamps while drawing an arc to fuse the opposed foil surfaces together. The clamps are then released, the jacketed duct removed from the welding apparatus and the radially extending, fused foil bead pressed parallel to the outer face of the duct.

United States Patent Terry 7 JACKET FOR CYLINDRICAL ARTICLE AND METHODAND APPARATUS FOR FORMING SAID JACKET Inventor:

[73] Assignee: Johns-Manville Corporation, New

York, NY.

Filed: Mar. 6, 1972 Appl. No.: 232,310

Related US. Application Data Division of Ser. No. 845,404, July 28,1969, Pat. No. 3,660,890.

[5 6] References Cited UNITED STATES PATENTS v 8/1955 Bowman 219/60 R X7/l96l Stanton et al... 219/62 X 12/1970 Huck 2l9/62 X 4/1963 Ferreruela219/60 R Primary Examiner-C. L. Albritton Attorney-John A. McKinney etal.

[57] ABSTRACT A duct of thermal insulation is jacketed with a gas im-Rupert DouglasTerry, Toledo, Ohio \Jan. 15, 1974 permeable sheetmaterial with a longitudinal seam formed by turning the mating ends ofthe sheet material outwardly and thermally fusing those ends into alinear nodular bead. In the case of metal foils of a few thousandths ofan inch in thickhess the bead is of the order of a thirty-second of aninch and is turned into the foil jacket to present a smooth non-cuttingsurface.

Semi-butt welds of foil are made by clamping the foil in face to facerelationship along an essentially line contact and moving an arc weldingelectrode with associated gas jets for a non-oxidizing gas parallel toand in close spaced relation to. the clamp line. Jacketing for preformedducts of glass or other fiber type insulation is drawn from a supply ofsheet stock to form a catenary loop in which a preformed duct is placed.Jaws forming unitary clamps and welding electrodes are closed to closethe opposite sides of the loop of foil around the duct and upone'achother. The foil is severed closely adjacent the clamps'and theelectrode with its jets for the gas is moved along the exposed edges offoil adjacent the electrode clamps while drawing an arc to fuse theopposed foil surfaces together. The clamps are then released, thejacketed duct removed from the welding apparatus and the radiallyextending, fused foil bead pressed parallel to the outer face of theduct.

9 Claims, Drawing Figures PATENTED JAN 1 5 I974 SHEET 1 0F 3 PATENTEDJAN15 I974 SHEET 3 OF 3 Fl G. 7

JACKET FOR CYLINDRICAL ARTICLE AND METHOD AND APPARATUS FOR FORMING SAIDJACKET Thisis a division of application Ser. No. 845,404, filed July 28,1969, now U.S. Pat. No. 3,660,890.

BACKGROUND OF THE INVENTION This invention relates to jackets forcylindrical articles and to methods and apparatus for encompassingarticles with jacketing material and joining the jacketing material.

More particularly, it relates to closing a sheet of foil upon itselfwhile encompassing a body to form a jacket therefor.

Heretofore great difficulty has been experienced in joining thin sheetmetal by welds of the butt type even in materials such as ferrous sheetwhich are readily welded in thick bodies. The materials are difficult tomaintain in weldable relationship, they are prone to distort underwelding temperatures, they tend to puncture during welding due toexcessive melting, oxidation is difficult to avoid, and in someinstances, a tendency to adhere to the electrodes or clamps isexperienced.

One form of the present invention is an aluminum foil jacketed duct ofglass fiber mat having a longitudinal fusion weld to provide a gasimpervious envelope. Heretofore, effort to jacket similar duct withaluminum has been made where the foil was overlapped and joined with abonding agent such as a resin adhesive. Such bonds were less thansatisfactory since the adhesive was applied to the non-porous foil andhad no opportunity to penetrate and develop a keyed coupling with thefoil. When bonded with cement, it had a low melt index, a lack ofsolvent escape, and an inability to pass certain fire and safety tests.More recently ultrasonic welds have been attempted. Such welds were imade on circumferentially overlapped portions of foil by inserting anunderlying anvil between the foil and the preformed, glass mat, tube.The labor cost for ultrasonic bonds were high, manipulation required forwithdrawal of the anvil disfigured the jacket, the excess foil requiredin the overlap was wasteful, the resultant sharp edge was exposedand-was a hazard, and the ultrasonic welding equipment was excessivelyexpensive.

SUMMARY OF THE INVENTION internal of a jacket of sheet material appliedto a cylindrical article.

A third object is to avoid the formation of hazardous edges on the foiljacket of duct.

A feature of the jacket of this invention is the formation of a bondbetween mating outwardly turned edges of the sheet material of thejacket as a nodular head This bead presents no sharp edges and in thecase of its development by thermal welding of aluminum foil, it isreadily pressed against the surface of the jacket to form a smooth outersurface for the finished product.

Another feature is the method of forming a jacket of sheet material on acylindrical article by fixing the material along a first straight edgewith a portion of the surface engaging the article turned outward,carrying the sheet material around the body to meet the turned portionwith another portion of that surface which is also turned outward, andforming a bond between the out turned ends of those meeting portionsclosely adjacent the cylindrical article.

Apparatus for jacketing a cylindrical article with sheet materialincludes as one'feature a stationary bar having a tungsten rod alongitsedge and a series of clamps which can be brought to bear on a face ofthe bar to clamp one edge of a strip of foil thereon.

Another feature is a complementary movable bar having a tungsten rodedge as a second elementcooperating with the first bar to form a jacketclamp. Foil is first draped as a catenary between the bars with theiredges separated. The edges are then closed upon the interveening twolayers of foil to draw the foil taut on the cylindrical article.

A further feature of the apparatus is an adjustable table or platformenabling the apparatus to accommodate bodies of various sizes andmaintaining the body in proper relationship to the jacket clamps so thatupon closing the clamps the supply end of the jacket material is drawntaut upon the body.

A sixth feature of the apparatus is a carriage or trolley which carriesa foil severing means and the welding electrodes and gas jets along theregion adjacent the jacket clamps.

Another feature is the essentially butt type weld achieved with thinfoils without tooling internal of the resulting jacket whereby theremoval of the jacketed element from the apparatus is facilitated,disfiguration of the jacket by distortion is minimized, and the trimmingof the completed joint is eliminated.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective of a section ofjacketed'air duct having a welded seam exaggerated in size to illustratethe radially protruding weld bead and its form as turned parallel to thejacket according to this invention;

FIG. 2 is an endview of the apparatus for forming the jacket of FIG. 1in accordance with the method of this invention with the apparatus asconditioned for initiation of the production of a jacketed duct;

FIG. 3 is an end view as in FIG. 2 with the free end of the jacketingfoil secured in the apparatus; and

FIG. 4 is an end view as in FIG. 2 with the jacketing foil clampedaround the duct underbody, the foil end clamp retracted and theapparatus conditioned for trimming the foil preparatory to welding theclamped ends.

FIGS. 5 through 7 are detailed views of a foil end clamp in its variouspositions of retraction, advance and clamping condition;

FIG. 8 is an enlarged end view of the foil trimming blade, and thecompositewelding electrode and gas supply manifold; and

FIG. 9 is a front view of the apparatus of FIGS. 2, 3 and 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A circular air duct 11 made upof a tube of matted glass fibers l2 and having an aluminum foil jacket13 is shown in FIG. 1. The glass fiber structure 12 can be made by theconventional gas attenuating processes and combined in mat form with aresinous or other adhesive bonding agent to bond the fibers into adurable, resilient, self-retaining mat. The bonded mat is wound upon amandrel and subjected to heat and pressure to impart the final ductshape to the fibrous mass. Although glass fibers are preferred due totheir ease of formation andlow cost, other common materials which can befiberized can be employed exclusively or in part in the formation of themat. These may include known products manufactured from various sourcematerials of silicates of metal oxides, such as rock wools, fromargillaceous matter or shale, slag wool from metallurgical slags, eachcommonly referred to as mineral wools," aluminum silicate fibers, andany fibers of the so-called glasses. The final duct shape can be otherthan a right circular cylinder, for example, it can be elliptical orgenerally rectangular in cross section.

A gas impervious jacket of aluminum foil is formed around theself-sustaining tubular structure 12 by placing a sheet of aluminum foilaround the structure, clamping the interior faces of opposite sides ofthe sheet together at a position closely adjacent the tubular structure12, and welding those faces together. The foil edges, when of 0.003 inchthick aluminum and when clamped together with about one-eighth inchprotruding beyond the clamping means fuses into a nodular bead 14 ofless than one-sixteenth inch in height extending radially from thejacket 13 and by virtue of its ductility can be formed essentiallyparallel to the jacket, as shown at 14a in FIG. 1, by wiping across thebead with a pressure sufficient to turn the bead without distortingduct, as with a block of wood. The resultant joint between the ends ofthe foil has been termed a semi-butt weld in that it is a gas imperviousjoint of fused aluminum derived from the foil itself with nocircumferential overlap other than that of the turned bead 14a. Theoverlap is of the order of a 30 second of an inch and offers anessentially smooth and continuous outer surface for the final productpresenting no sharp edges which would behazardous to those handling theduct.

Apparatus for applying the foil jacket is disclosed in its variousstages of utilization in FIGS. 2 through 4. It comprises a frame 15including a base 16. A set of stanchions 17 extend upward from the base16 at its front for supporting a control panel 18, guards l9 and atrolley assembly 21. A pair of end stanchions 22 provide a rail and abase for rack 23 whereby a table 24 positioned within the frame can beadjusted in its elevation for supporting workpieces, as structure 12 inFIG. 4, for jacketing. A roll stand 25 extends upward from frame base 16to support a, coil 26 of foil for rotation.

A range of sizes of glass fiber mat structures 12 can be accommodated inthe region of the illustrated apparatus. In each jacketing process theupper face of the cylindrical article 12 is positioned in region 20 withits longitudinal axis horizontal so that it is immediately below thehorizontal stationary jaw 27 of a unitary foil clamp and electrodestructure 28 as shown in detail in FIGS. 5 through 7 in order to enablethe foil jacket to be clamped closely adjacent the structure. Table 24is adjustable in its height to enable the proper orientation of each ofa range of sizes of mat structures 12. Each of stanchions 22 has opposedflanges, one of which supports rack 23 and the other of which provides arail upon which rollers 29 ride. A table support car is formed by sidebars 31 at each stanchion extending to an end panel 32 upon whichrollers 29 are journaled and from which a transverse rod (not shown)extends to the opposite end panel. Drive shaft 34 is journaled in a boss35 on the end of each side bar opposite its end panel and has a pinion(not shown) engaged with rack 23, a suitable means of rotation such ashand crank 37 and suitable means to maintain the adjusted position suchas a brake (not shown) on shaft 34.

Circular mat structures 12 are confined within region 20 by thesemicircular guides 38 in frame 15 to tend to center the structures withrespect to the clamp and electrode 28.

A movable clamp and electrode jaw 39 is mounted on a series of L-shapedarms 41 pivoted on shaft 42 secured in base 16. This jaw is moved in anarc around shaft 42 by means of pneumatic cylinders 43 having theirblind ends pivoted at 44 to base 16 and their piston rods 45 pivotallyconnected to arms 41. Controls for the positioning of jaw 39 areprovided on control panel 18 so that it can either be retracted from jaw27 as shown in FIG. 2, or brought into clamping relationship with jaw 27as shown in FIG. 4.

The initial step in forming a jacket is to draw foil from coil 36, andclamp its free end across its width against the upper face of bar 27forming the stationary jaw. The foil forms a catenary between the coiland the jaw 27. The free end of the foil strip is clamped by clampingfeet 48 each of which is carried on a lever 49 pivotally connected by acrank 51 on control rod 52 and guided between rollers 53 carried by aguide bail 54 secured to a support beam 55. A control lever 56 issecured to control rod 52 so that its movement from the position shownin FIGS. 2 and 5 to that shown in FIG. 6 and finally to that shown inFIGS. 3 and 7 causes the feet 48 to be extended to a position adjacentthe free edge ofjaw 27 and to be brought into engagement with the upperface of the jaw to clamp the end of the foil.

Tubular mat structure 12 is placed in the catenary formed by the foilwith table 24 adjusted to a height below jaw 27 slightly greater thanthe outer diameter of the structure in the case of a circular duct. Jaw39 is then moved to clamping relationship with jaw 27 to center the matstructure 12 below the closed jaws 27 and 39, draw the foil taut overthe mat structure 12 and clamp the inner faces of the mating foilportions together. The apparatus is thus conditioned as shown in FIG. 4.

The sheet material of the jacket 13 is in this manner carried around theperformed duct 12 and turned outwardly therefrom where the oppositesides meet. The face of the material which engages the duct in theregion turned outwardly on each of the mating sides are maintained inabutting relation. These regions are carried over edges having smooth,convex curved, cross sections along straight lines so that the seam atthe mating edge when trimmed close to the clamping elements appears as adouble thickness of the jacket material extending generally radiallywith the two layers having a slight tendency to diverge from each other.

The clamped foil is severed from the supply and from the clamped freeend along a line closely adjacent and paralleling the unitary clamp andelectrode jaws 27 and 39. One means of accurately cutting the foil is bymeans of a blade 57 mounted on a carriage 21 which also carries awelding assembly 58. The carriage is guided along a path paralleling theclamping jaws 27 and 39 by means of a pair of rails 59 in the form ofcircular rod and a drive screw 60. Sliding bearings 59a couple thecarriage to rods 59 and a split nut (not shown) provides drivingengagement between the carriage and drive screw 60. The screw 60 and nutcan be arranged for bidirectional drive or can be arranged to bereleased so that the carriage can be manually moved from one end of thetrack to the other to sever the foil and can be driven at a controlledrate of advance in the opposite direction for welding the protrudingfoil ends.

In initially securing the free end of the foil, a short length, about aninch, of material is positioned upon the upper face of jaw 27, controllever 56 (FIGS. 5 to 7) is rotated clockwise as viewed in FIGS. 2 to 7so that rod 52 carries cranks 51 in a clockwise direction to clamp feet48 on the foil end After the jaw 39 is engaged with jaw 27, the clampingaction of feet 48 is no longer required and the region adjacent theclosedjaws is cleared by retraction of the feet 48. Lever 56 is rotatedcounter-clockwise to raise feet 48 and retract them as shown in FIGS. 4and 5. The blade 57 is arranged as shown in FIG. 8 to be located withinabout a sixteenth of an inch of the jaws 27 and 29 and is moved alongthose jaws without interference with the retracted feet 48. The free endof the foil and that portion extending to the foil source, coil 26, areeach severed from the clamped jacketing foil 13 to present about asixteenth of an inch ofa double thickness of the foil protrudingradially from the duct.

FIG. 8 isan enlarged side view of a portion of the fiber tube 12, thefoil jacket 13 and its clamped ends 61. Blade 57 is maintained generallyparallel to jaw 27 by its holder rod 62 to which it is secured as bymachine screws 63. The carriage 21 supports holder rod 62 so that it canbe adjusted as by means of the slot 63a and thumb screw 64. The angularposition of the cutting edge of the blade with respect to foil ends 61can also be adjustable where that relationship is significant ineffectively shearing the foil.

Welding head 58 is supported on carriage for adjustment with respectthereto. Ordinarily, it is oriented so that its electrode tip 65 iscentered above the two ends 61 with a spacing therefrom of about onesixteenth to one quarter of an inch with one eighth inch beingpreferred. Tip 65 is mounted in a holder 66 and maintained coaxial witha gas manifold 67 by the end closure 68 at the lower end of the manifoldand suitable spider supports (not shown) to the holder. Adjustment ofthe electrode and manifold position relative to carriage 21 is providedby the coupling therebetween as by a collar 69 which can be mounted forrotation and reciprocation as by a machine screw in a slot on thecarriage (not shown) and has a clamping screw 71 to secure the manifold67. Helium is supplied to the manifold from tank 72 (FIG. 9) throughflexible tubing 73 which also encloses the conductor 74 to electrodeholder 66 and electrode 65.

Welding of the foil ends is by a conventional inert gas-arc processwherein electrode 65 is'suitably supplied with electrical energy from acommercial welding control 75. The electrode encompassing gas manifold67 has an array of apertures 76 from which jets are directed toward thewelding tip. A refractory skirt 77 confines the gas issuing from themanifold 67 to the region of the arc to form an inert envelope of gasaround the fused aluminum and the electrode. The electrode 65 isinsulated from the remainder of the apparatus and from the gas supply 72and gas controls 78. It is con nected to the welding controller byconductor 74 through junction box 79 and conductor 81. The controller 72is also connected to the frame 15 of the welding apparatus maintained atground potential by a grounding conductor in cable 82.

The cooperating welding electrodes are tungsten rods 83, as best seen inFIGS. 5 through 8,- secured to the clamping edges of clamping jaws 27and 39 as by silver solder to afford good heat conductivity from theweld to the heat sink provided by the blades and their supportingstructure. Tungsten clamp rods have the further advantage thatthey'eliminate any tendency to adhere to the aluminum foil. This releasecharacteristic is important where all pin holes are to be avoided in theseam 14 as in the case of air duct jacketing.

In practice, the jacket has been formed of aluminum foil of 0.002 inchand 0.003 inch thickness using circular tungsten rod of 0.040 inchdiameter as the clamping edges and electrodes 27 and 39. These edges areclosed upon the intervening foil by the operator manually actuating bothcontrol knobs of FIG. 9. With the jaws 27 and 39 closed, the carriagedrive nut is opened and the carriage 21 is slid from the right end tothe left end of its travel as viewed in FIG. 9. Guard 86 obscures thecarriage, its drive and guide mechanism in FIG. 9. This motion ofcarriage 21 causes blade 57 to trim the foil seam to the form of theradially protruding' ends 61 of FIG. 8. A weld is made by fusing theprotruding ends 61 by striking an are between electrode tip 65 and theends and causing carriage to advance along the seam from the left end tothe right end as viewed in FIG. '9.

A nodular bead is formed by meltingthe ends 61. No filler material isrequired since the protruding ends provide sufficient material for theweld. As inert atmosphere such as argon or helium is maintained aroundelectrode 65 and the molten aluminum during the weld by setting the gasflow controls 78 to pass about 5 cubic feet per hour from tank 72through tubing 86 to control box 79 where the conductor 74 is introducedinto the tube 73 which conveys the gas from tube 86 to manifold 67.

In welding aluminum foil, the arc is struck by superimposing a highfrequency signal on the regular sixty cycle alternating welding current.The are is instituted by the operator by manually operating switch 87which is effective through control box 88 and cable 82 to welder 75 toactuate the welding control. The superimposed high frequency issustained in the case of aluminum foil in order to insure the continuityof the arc throughout the travel of the electrode 65 along the creasedas the apparatus is refined.

Motor 89 drives screw 60 through a clutch and suitable linkage (notshown) within housing 19. The clutch is engaged at the time the weldingarc is struck in response to actuation of switch 87. Termination of thearc and release of the clutch is controlled by a limit switch (notshown) which is responsive to the travel of carriage 21 to its limit onthe right side of FIG. 9. Motor speed can be adjusted by means of anysuitable motor speed control (not shown) to adjust the speed of advanceof the carriage 21.

Welding current of from 35 to 40 amperes is drawn at a voltage of tovolts with the parameters noted above. At slower speeds of carriageadvance the current is reduced and at higher speeds it is increased.

Upon completion of the traverse of carriage 21 to form the weld bead 14along the entire length of the jacket 13, the control switch 91 ismanually operated by the operator to retract jaw 39 The jacketed duct isremoved from the region 20 to clear the apparatus for another jacketingoperation.

The present invention has been applied to aluminum foil of thickness of2 mills and greater employing a helium shielding envelope to jacketfiber glass air duct. However, it is to be appreciated that certainaspects of the method and apparatus can be applied to otherjacketingmaterials and that other metallic foils can be applied as jacketsaccording to the disclosure. Further, cylindrical articles other thanthe disclosed air duct can be jacketed according to this invention.Variations in the apparatus as in the foil clamps 48, the carriage 21,the trimmer 57 and the bonding means of electrode 65 can be made. Themethod of applying the jacket to a cylindrical article can beaccomplished by other than the apparatus illustrated and evenby hand.For example, the edges of the sheet material can be secured to manuallymanipulate complementary elements to close the jacket material uponitself and around the article to be jacketed and the bonding of theclosed edges accomplished by other means than the welding electrodeshown. Thus the disclosure is to be read as illustrative of theinvention and not in a limiting sense.

I claim:

1. Apparatus for jacketing a cylindrical article comprising:

a. coil support means for supporting a coiled sheet of jacketingmaterial,

b. first elongate jaw means for engaging the jacketing material in afirst region along a first line extending across the width of the sheet,

c. second elongate jaw means for engaging the jacketing material in asecond region along a second line spaced from the first line andextending across the width of the sheet,

d. clamping means for clamping the jacketing material along the firstjaw,

e. means for moving the first and second jaws between an open positionwhere the jaws are spaced apart a distance sufficient to permit theplacement of a cylindrical article on the sheet of jacketing materialand a closed position where the first and second jaws clamp the tworegions of the sheet together and a portion of the sheet intermediatesaid first and second regions about the cylindrical article, and

f. bonding means external of said jaws for thermally bonding the firstand second regions of the sheet together when the jaws are in the closedposition.

2. Apparatus as defined in claim 1 and further comprising:

means for severing the sheet adjacent said first and second regions toseparate the portion of the sheet that is clamped about the cylindricalarticle from a remainder of the sheet.

3. Apparatus as defined in claim 1 and further comprising:

means for moving the clamping means into and out of clamping relationwith the first jaw so that the clamping means can be withdrawn from thefirst jaw during the bonding of the regions.

4. Apparatus as defined in claim 25 wherein said jacketing material ismetallic foil and said bonding means is a welding electrode for weldingtogether said regions engaged by said jaws and the electrode is mountedon a carriage, and means for moving said carriage along the jaws whenthe jaws are in the closed position.

5. Apparatus as defined in claim 4 including a gas manifold associatedwith said welding electrode mounted upon said carriage said manifoldhaving an aperture to direct gas toward a molten region of the weldbonding the regions of the sheet; and means supplying a non-oxidizinggas to said manifold in an amount sufficient to maintain an envelope ofnonoxidizing gas around the molten region of the weld.

6. Apparatus as defined in claim 1 including a support for thecylindrical article to be jacketed; and means mounting said support tomaintain the article with one side thereofin close proximity to an innerside of said jaws when said jaws are closed upon each other.

7. Apparatus as defined in claim 6 wherein said jaws engage said sheetalong straight, horizontal lines; and wherein said article supportmaintains the longitudinal axis of said article horizontal and belowsaid closed jaws, whereby said article is encompassed by a subjacent,pendant loop of the sheet which is drawn closed above said article assaid jaws are closed.

8. Apparatus as defined in claim 6 wherein said means mounting saidsupport is adjustable in its position relative to said jaws whereby arange of sizes of cylindrical articles can be accommodated.

9. Apparatus as defined in claim 4 wherein said jaws in the area of theline of engagement with the metal foil are tungsten of a smooth convexcurved cross section. 1:

0 L UNITED-STATES PATENT OFFICE I I o CERTIFICATE OF CORRECTION ;.N-3.786.226" Dated, m 1914 o y W I IIVBHt i-W Rupeffit Dbflgla Trrj If isoe rt ifie dthat e rror appears in the above identified patent and thatsaid Letters Patent are hereby corrected as' shown below:

comm, lit 1e v31, "36" should read --26--. "1 Column 6, line 42, "As"'should read --An-.

; Column 8, line '28, (Claim 4) "25" should read -l-.

signed sealedthis 9th day of July 197 (SEAL) Attest t v I MCCOY M;GIBSOMJR, y L c. MARSHALL DANN Atte s'bing Offioer' Commissioner ofPatents t J IT D STATES PATENT OFFICE? 5; CERTIFICATE OF CORRECTIONPotent; No. 3,735,226 Dat e'd, Janna-n! 15 1914: m

Inv nt r( Ru ert,Dou las Torry I It is cerrlfie d that error appears in'the' above-ideu tified pareut \and thgt s ai dL er tors Patent arehereby corrected as shownbelow:

Column 4, limo 31,. 7'36" should read --26--. l Column 6, line 42, "As'?should read -An--.

Column 8, line 28, (Claim 4) "25" should read l.

g h seal d this 9th day u Y 4P- s-mm 1 *Attest: V

ma aIBsomJR, l l L c.- MARSHALL 1mm r m d AttestingDffiggr Commissionerof Patents C

1. Apparatus for jacketing a cylindrical article comprising: a. coilsupport means for supporting a coiled sheet of jacketing material, b.first elongate jaw means for engaging the jacketing material in a firstregion along a first line extending across the width of the sheet, c.second elongate jaw means for engaging the jacketing material in asecond region along a second line spaced from the first line andextending across the width of the sheet, d. clamping means for clampingthe jacketing material along the first jaw, e. means for moving thefirst and second jaws between an open position where the jaws are spacedapart a distance sufficient to permit the placement of a cylindricalarticle on the sheet of jacketing material and a closed position wherethe first and second jaws clamp the two regions of the sheet togetherand a portion of the sheet intermediate said first and second regionsabout the cylindrical article, and f. bonding means external of saidjaws for thermally bonding the first and second regions of the sheettogether when the jaws are in the closed position.
 2. Apparatus asdefined in claim 1 and further comprising: means for severing the sheetadjacent said first and second regions to separate the portion of thesheet that is clamped about the cylindrical article from a remainder ofthe sheet.
 3. Apparatus as defined in claim 1 and further comprising:means for moving the clamping means into and out of clamping relationwith the first jaw so that the clamping means can be withdrawn from thefirst jaw during the bonding of the regions.
 4. Apparatus as defined inclaim 25 wherein said jacketing material is metallic foil and saidbonding means is a welding electrode for welding together said regionsengaged by said jaws and the electrode is mounted on a carriage, andmeans for moving said carriage along the jaws when the jaws are in theclosed position.
 5. Apparatus as defined in claim 4 including a gasmanifold associated with said welding electrode mounted upon saidcarriage said manifold having an aperture to direct gas toward a moltenregion of the weld bonding the regions of the sheet; and means supplyinga non-oxidizing gas to said manifold in an amount sufficient to maintainan envelope of non-oxidizing gas around the molten region of the weld.6. Apparatus as defined in claim 1 including a support for thecylindrical article to be jacketed; and means mounting said support tomaintain the article with one side thereof in close proximity to aninner side of said jaws when said jaws are closed upon each other. 7.Apparatus as defined in claim 6 wherein said jaws engage said sheetalong straight, horizontal lines; and wherein said article supportmaintains the longitudinal axis of said article horIzontal and belowsaid closed jaws, whereby said article is encompassed by a subjacent,pendant loop of the sheet which is drawn closed above said article assaid jaws are closed.
 8. Apparatus as defined in claim 6 wherein saidmeans mounting said support is adjustable in its position relative tosaid jaws whereby a range of sizes of cylindrical articles can beaccommodated.
 9. Apparatus as defined in claim 4 wherein said jaws inthe area of the line of engagement with the metal foil are tungsten of asmooth convex curved cross section.